(a) Field of the Invention
The present invention relates to a precursor composition of an oxide semiconductor, a thin film transistor substrate including the oxide semiconductor, and a method of manufacturing the thin film transistor substrate including the oxide semiconductor.
(b) Description of the Related Art
A liquid crystal display is currently one of the most widely used flat panel displays, and a device that includes two substrates on which electrodes are formed and a liquid crystal layer interposed therebetween, and controls the intensity of transmitted light to display an image by rearranging the liquid crystal molecules of the liquid crystal layer by applying voltage to the electrodes.
In general, the liquid crystal display includes a thin film transistor for switching a pixel. The thin film transistor includes a gate electrode receiving a switching signal, a source electrode to which data voltage is applied, and a drain electrode outputting a data electrode as three terminals to constitute a switching element. Further, the thin film transistor includes an active layer overlapping the gate electrode, the source electrode and the drain electrode as a channel layer, and the active layer mainly uses amorphous silicon as a semiconductor material.
However, in accordance with enlargement of the display, there is an urgent need for developing a thin film transistor that can be driven at ultra-high speed. Particularly, amorphous silicon that is currently used as the active layer has low electron mobility and requires costly vacuum process-based deposition equipments for applying a chemical vapor deposition (CVD), a sputtering method or the like.
Accordingly, there is a need to develop an oxide semiconductor material having high electron mobility and capable of being subjected to a solution process in order to be performed through a coating process or a ultra low-priced printing process. However, heat treatment is required at a high temperature of 400° C. or more in order to form the oxide semiconductor by the solution process, and energy consumption is large. Further, since a costly additive is added to a precursor of the oxide semiconductor for the low temperature process, it is difficult to reduce cost.
Meanwhile, there is a need for developing a thin film transistor substrate that can be used in a flexible display device such as electronic paper and can be formed by the low temperature process.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.